Basic management of the sixth day file and XFS system backup recovery

1.1 Linux system directory structure, relative path/absolute path

1.1.1 Linux System directory structure

Everything in the Linux system is a file.

/ root directory, the beginning of everything, like a branch, he is the root of all forks

/bin

In single-user mode, the common Linux commands you need to use are located in this directory. The commands used by all users of the system are set here.
For example: PS, ls, ping, grep, CP

/sbin

Just like/bin,/sbin also contains binary executables.
However, Linux commands in this directory are usually used by system administrators to maintain the system. Example: Iptables, reboot, Fdisk, ifconfig, swapon commands

/boot

The files that need to be loaded when the system starts are here

/ dev storage device files are also seen as files in the Linux system North

/ etc Store system configuration file, and program configuration file

There are many, according to the English name can know its configuration purposes

such as ABRT---interrupt environment environment

/etc/environment is the environment that sets up the entire system, and/etc/profile is the environment for setting up all users, regardless of the login user, which is related to the logged-on user

Home for all ordinary users, storing data for ordinary users

/root The Super User's home, storing the Superuser's data

/lib System library files have static library and dynamic library program compile and run rely on

/lib64 System 64-bit library file

/media Removable multimedia device

/mnt for mounting

/opt This casual use

/proc can view system status

Contains information about the system process.
This is a virtual file system that contains information about the processes that are running. For example: The/proc/{pid} directory contains information related to a specific PID.
This is a virtual file system in which system resources exist as textual information. Example:/proc/uptime

Cat Meminfo #查看内存使用状态

Cat Cpuinfo #查看cpu运行状态

/run

Well, I'm not quite sure what he's storing, and it looks like the system running state.

Now know that its predecessor was/var/run

/srv

The SRV Representative service.
Contains data related to server-specific services.
For example,/srv/cvs contains CVS-related data.

/sys

Fixed information that should be stored on the system hardware

/tmp

Contains system and user-created temporary files.
When the system restarts, the files in this directory will be deleted.

/usr

Source code that contains binaries, library files, documents, and level two programs.
The/usr/bin contains a binary file of the user program. If you can't find the user binaries in/bin, go to the/usr/bin directory to see. For example: At, awk, CC, less, SCP.
The/usr/sbin contains the system administrator's binaries. If you can't find the system binaries in/sbin, go to the/usr/sbin directory to see it. For example: ATD, Cron, sshd, Useradd, Userdel.
The/usr/lib contains the libraries used by/usr/bin and/usr/sbin.
The user program installed from the source is included in the/usr/local. For example, when you install Apache from the source, it will be in/usr/local/apache2.

/var

var represents a variable file.
This directory allows you to find files that may grow in content.
This includes-system log files (/var/log), Package and database files (/var/lib), e-mail (/var/mail), print queue (/var/spool), lock Files (/var/lock), multiple restarts of required temporary files (/var/tmp) ;

1.1.2 Relative Path/absolute path

Relative paths are relative to the current position, so generally. Or.. Beginning

The absolute path is relative to/, so it is usually preceded by/

Very well differentiated

1.2 Create/Copy/delete files, RM-RF/accidents

1.2.1 Create: Touch

Format: Touch file name

Example: Touch a.txt

1.2.2 Copy: CP

Format: CP source file target file #可带路径

Add parameter-rf to copy directory

-R Recursive Replication recuursively

-F does not prompt force

1.2.3 Delete: Rm/rmdir

Format: RM target file

rm-d Directory Name

-d The file to be deleted is an empty directory

Adding the-RF parameter can also be deleted unless an empty directory

-r-f meaning with CP

1.2.4 Rename/move: MV

MV original filename new file name #重命名

Add a path to the file name to experiment with moving

Such as:

MV A.txt bbb.txt #将文件a. txt renamed to Bbb.txt

MV A.txt/root #将a. txt moves to the/root directory

1.3 Viewing the contents of a file

Cat file name

More File name | Less file name

If the file text is more, you can use these two commands to view, distinguish yourself research it

Head File name | Tail file name

View file header or end of file

Add-n parameter to view the file header n rows or the reciprocal n rows

To view a row of a file individually, you can use the channel

Example: View line 3rd of the A.txt file

Head-3 A.txt | Tail-1

1.4 Combat: Backup and Recovery of XFS file systems

First step: Shut down the system first, add a hard disk

The rest of the way by default, then click OK, then boot

Step two: View the file name of the newly added hard disk as SDB and partition the SDB

Follow the instructions on the command prompt:

Enter N to add a new partition

Enter p to create a primary partition

Number and location default, direct carriage

Enter the new partition size of 1G, which is input +1g, enter,

Enter W to perform partition operation, partition new

Step three: Format the newly created partition, using the MKFS.XFS

You can also use the Mkfs-t xfs/dev/sdb1 command

Fourth step: Mount the/DEV/SDB1 partition

Fifth step: Copy a file to the/SDB1 directory, create a new directory into the/SDB1 directory and leave it for testing

Sixth step: Backing up the file system

[Email protected] ~]# xfsdump-f/OPT/DUMP_SDB1/DEV/SDB1
xfsdump:using file Dump (drive_simple) strategy
Xfsdump:version 3.1.4 (Dump format 3.0)-type ^c for status and control

============================= Dump Label Dialog ==============================

Please enter the label for the dump session (timeout in SEC)
dump_sdb1_20160802
Session label entered: "dump_sdb1_20160802"

---------------------------------End Dialog---------------------------------

Xfsdump:level 0 Dump of XIAOGAN.120:/SDB1
Xfsdump:dump Date:tue 2 23:56:53 2016
Xfsdump:session id:d850eaf1-d2f6-4a3e-b694-0a9547017754
Xfsdump:session Label: "dump_sdb1_20160802"
Xfsdump:ino map Phase 1:constructing initial Dump list
Xfsdump:ino map Phase 2:skipping (no pruning necessary)
Xfsdump:ino Map Phase 3:skipping (only one dump stream)
Xfsdump:ino Map Construction Complete
xfsdump:estimated dump size:25536 bytes
Xfsdump:/var/lib/xfsdump/inventory Created

============================= Media Label Dialog =============================

Please enter the label for media on Drive 0 (timeout in sec)
media0
Media label entered: "Media0"

---------------------------------End Dialog---------------------------------

Xfsdump:creating dump Session Media file 0 (media 0, file 0)
xfsdump:dumping ino Map
xfsdump:dumping Directories
xfsdump:dumping non-directory Files
Xfsdump:ending Media file
Xfsdump:media File size 24232 bytes
Xfsdump:dump size (non-dir files): 2592 bytes
Xfsdump:dump complete:23 seconds Elapsed
Xfsdump:dump Summary:
Xfsdump:stream 0/opt/dump_sdb1 OK (Success)
Xfsdump:dump status:success

To view backup information:

You can also back up in a non-interactive way, with the following commands:

Xfsdump-f/opt/dump_sdb1/dev/sdb1-l dump_sdb1_20160802-m media0

-f Specifies the backup file directory

-L Assign Label session label

-m Specify Device label media label

Single File backup:

The-s parameter can back up a single file, but

Xfsdump-f/opt/dump_passwd-s/sdb1/passwd-l dump_passwd-m passwd

-S cannot be followed directly by the path, it should be the following:

Xfsdump-f/opt/dump_passwd-s passwd/sdb1-l dump_passwd-m passwd

Seventh Step: File Recovery, delete file manufacturing false Delete illusion, and then use the Xfsrestore command to recover files

Command: Xfsrestore-f/opt/dump_sdb1/sdb1

Recover individual Files!!!

Basic management of the sixth day file and XFS system backup recovery